ON  THE  SOLVENT  POWERS  OF  SIMPLE  SYRUP.  293 
freshly  precipitated  subnitrate  is  more  or  less  soluble,  about 
2  grs.  in  the  ounce  of  syrup  dissolving. 
Calomel  was  next  tried,  but  it  was  found  impossible  to  get 
rid  of  the  syrup  without  losing  the  mercury. 
Sulphur,  phosphate  of  lime,  sulphate  of  baryta,  iodide  and 
chloride  of  silver,  carbonate  of  lead,  camphor,  and  many  other 
insoluble  substances,  but  without  any  positive  results.  Chlorine, 
iodine  and  bromine  were  more  soluble  in  syrup  than  in  water, 
and  the  solutions  were  more  permanent. 
Carbonate  and  phosphate  of  iron  were  found  insoluble. 
The  writer  finding  it  impossible  to  prepare  proto-carbonate 
of  iron  by  the  officinal  process  (vide  Pill.  Ferri  Carb.)  devised 
the  following  method,  by  which  nearly  pure  proto-carbonate  was 
made.  Proto-sulphate  of  iron  was  first  made  by  Bonsdorff's  pro- 
cess. A  distillatory  receiver  was  then  fitted  with  a  funnel  and 
the  tubulure  was  tied  over  with  a  rag.  The  sulphate  of  iron 
hot  was  poured  in,  and  then  boiling  solution  of  carbonate  of 
soda.  The  precipitate  was  washed  with  hot  boiled  water,  and  as 
soon  as  the  washings  ceased  to  precipitate  chloride  barium, 
<  Syrupus'  was  added  by  the  funnel,  and  the  whole  poured  into  a 
dish ;  it  was  pure  carbonate  of  iron  and  ready  for  use.  The 
process  consumes  about  twenty  minutes. 
Thus  far  we  have  been  treating  of  the  solvent  powers  of 
syrup.  We  wish  now  to  speak  of  a  matter  related  to  it3  solvent 
power. 
We  desire  here  to  enunciate  the  general  truth,  and  to  pro- 
mulgate it  as  a  truth  as  yet  unrecognized,  viz  :  That  many  sub- 
stances may  be  dissolved  in  syrup,  which  it  would  be  impossible 
to  dissolve  in  water,  for  the  reason  that  the  affinity  of  the  water 
in  the  syrup  for  the  dissolved  body,  or  its  solvent,  is  completely 
neutralized  by  the  affinity  of  the  water  for  the  sugar  of  the 
syrup.  In  other  words,  we  propose  to  antagonize  the  disposition 
of  the  water  to  unite  with  the  dissolved  body,  or  its  solvent,  by 
the  superior  disposition  of  the  water  to  keep  itself  united  with 
the  sugar.  For  instance,  it  is  impossible  to  swallow  Tinctura 
Camphorse.  If  you  mix  it  with  the  water,  this  latter  seizes  upon 
the  alcohol  of  the  tincture,  and  the  camphor  is  precipitated,  and 
if  you  swallow  this  camphor  mixture,  more  or  less  gastrodynia 
is  sure  to  result.    If,  however,  you  mix  the  tincture  with 
